Endoscopic end effectors constructed from a combination of conductive and non-conductive materials and useful for selective endoscopic cautery

ABSTRACT

A non-metallic end effector for use in an endoscopic surgical tool includes a metallic core for strength and for providing a selected electrode surface on the end effector. Selectively conductive end effectors are manufactured by insert molding a plastic or ceramic or other non-conductive body around a metallic or otherwise conductive core. The conductive core is exposed on a selected portion of the working surface of the end effector and extends through the non-conductive body of the end effector for coupling to an electrical source. Selectively conductive end effectors of this type can also be manufactured by coating a cast end effector member with a non-conductive polymer or by metallically plating a non-conductive ceramic end effector member. By extending the conductive core of a selectively conductive end effector member to the pivot hole of the member, electrical coupling can be made through the clevis and tube of an endoscopic instrument. By extending the conductive core to the actuation bore of an end effector member, electrical coupling can be made through the push rod or other actuation member in an endoscopic instrument. Using both techniques, a bipolar selective cautery end effector can be provided on an endoscopic instrument.

This application is a continuation of Ser. No. 08/107,454, now U.S. Pat.No. 5,396,900 which in turn is a continuation-in-part of Ser. Nos.07/922,023 now U.S. Pat. No. 5,331,971 (which is a continuation of Ser.No. 07/680,392 now issued as U.S. Pat. No. 5,192,298), U.S. Ser. No.07/978,249 now U.S. Pat. No. 5,395,375 entitled "Arthroscopic SurgicalInstruments", and U.S. Ser. No. 08/016,595 now abandoned entitled"Endoscopic Biopsy Forceps Devices with Selective Bipolar Cautery",which are hereby incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

This invention relates to endoscopic surgical devices. Moreparticularly, the invention relates to an endoscopic surgical toolhaving end effectors made out of a combination of plastic or ceramic andmetal and useful for selective endoscopic cautery.

Endoscopic surgery is widely practiced throughout the world today andits acceptance is growing rapidly. In general, endoscopic surgeryinvolves one or more incisions made by trocars where trocar tubes areleft in place so that endoscopic surgical tools may be inserted throughthe tubes. A camera, magnifying lens, or other optical instrument isoften inserted through one trocar tube, while a cutter, dissector, orother surgical instrument is inserted through the same or another trocartube for purposes of manipulating and/or cutting the internal organ.Sometimes it is desirable to have several trocar tubes in place at oncein order to receive several surgical instruments. In this manner, organor tissue may be grasped with one surgical instrument, andsimultaneously may be cut with another surgical instrument; all underview of the surgeon via the optical instrument in place in the trocartube.

Various types of endoscopic surgical instruments are known in the art.These instruments generally comprise a slender tube containing a pushrod which is axially movable within the tube by means of a handle ortrigger-like actuating means. An end effector is provided at the distalend of the tube and is coupled to the push rod by means of a clevis sothat axial movement of the push rod is translated to rotational orpivotal movement of the end effector. End effectors may take the form ofscissors, grippers, cutting jaws, forceps, and the like. Because oftheir very small size and the requirements of strength and/or sharpness,end effectors are difficult to manufacture and are typically formed offorged stainless steel. As such, they form an expensive portion of theendoscopic instrument.

Modern endoscopic procedures often involve the use of electrocautery.Indeed, several types of electrocautery devices for use in endoscopicsurgery are described in the prior art. U.S. Pat. No. 4,418,692 to Guay,for example, discloses a device for use in laparoscopic tubalcauterization for blocking the Fallopian tubes of a patient. The devicecomprises a substantially tubular body member having a spring-biasedpiston slidably mounted therein. A pair of electrodes (either monopolaror bipolar) are disposed to grasp living tissue when the piston is in afirst position biased by the spring and to release the tissue when abutton is pressed which moves the piston into a second position. Thedevice includes a circuit breaker which interrupts current flowing tothe electrodes when the piston is in the second position. When theelectrodes grasp the tissue, however, current is supplied to the entiresurface of the electrode, that is, both the grasping surface and theouter non-grasping surface.

Another electrosurgical instrument for use in combination with anendoscope is disclosed in U.S. Pat. No. 5,007,908 to Rydell for"Electrosurgical Instrument Having Needle Cutting Electrode andSpot-Coag Electrode". Rydell's device includes an elongated flexibletubular member with a plurality of lumens. The distal end of the tubularmember is provided with a bullet shaped ceramic tip covered with aconductive layer and having an opening coupled to a first one of thelumens. The conductive layer is coupled to a conductor which extendsthrough a second one of the lumens to an electrical source. A secondconductor, also coupled to the electrical source is slidable through thefirst lumen by a plunger. The two electrodes form a bipolar pair. In asecond embodiment, the conductive layer on the ceramic tip is split byan insulating gap and both halves of the tip form a bipolar pair ofelectrodes. As with the Guay device, above, substantially the entiredistal surface of Rydell's device serves as an electrode when energized.

Other electrocautery probes for use with an endoscope are disclosed inU.S. Pat. No. 3,920,021 to Hiltebrandt. Hiltebrandt discloses severaltypes of probes similar to Rydell's in that they have a substantiallybullet shaped tip with hemispheric or annular conductors formingelectrode pairs. Hiltebrandt also shows electrodes similar to Guay's; apair of springy arms slidable through a tube member to grasp and releasetissue. Of course, the gripping force obtainable by either Guay's orHiltebrandt probes is severely limited because the electrodes must be"springy".

It is known in electrosurgery to insulate a portion of the surface areaof an electrode so that only a precise or at least well defined portionof an electrode's surface is conductive. This is desirable in order toprotect both the surgeon and the tissue adjacent to the site ofelectrosurgery from accidental cautery by an electrode having a broadfully conductive surface. U.S. Pat. No. 3,100,489 to Bagley, forexample, shows cautery forceps where the entire surface of the forcepswith the exception of the forceps tips is provided with an overallpliable insulating coating of rubber or synthetic rubber-like material.U.S. Pat. No. 5,049,148 to Mehl discloses a "Radio Frequency HairRemoval Tweezer" which includes insulated tweezer arms with conductingpads at the tips of the arms so that RF energy can be applied toindividual hairs without burning surrounding skin through arcing.Nevertheless, it is heretofore unknown to selectively insulate portionsof an endoscopic end effector to provide a well defined and discreteelectrosurgical surface. It is also heretofore unknown to makeendoscopic end effectors primarily from plastic, as plastic is typicallyconsidered too weak to properly serve desired functions.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an endoscopicsurgical instrument with a cauterizing end effector where only a part ofthe surface of the end effector is electrically conductive.

It is also an object of the invention to provide a substantiallynon-conductive end effector with an electrically conductive reinforcingcore or skeleton.

It is another object of the invention to provide methods ofmanufacturing selectively conductive end effectors.

It is a further object of the invention to provide means forelectrically coupling a selected conductive surface of an end effectorto an electrical source.

It is yet another object of the invention to provide means forelectrically coupling selected conductive surfaces of two end effectormembers to an electrical source for bipolar cautery.

It is still another object of the invention to provide a non-metallicend effector having a strength enhancing metal spine.

In accord with these objects which will be discussed in detail below,the present invention includes an endoscopic surgical instrument havinga tube with a push rod or wire axially movable therein and coupled atits proximal end to an actuator. An end effector is coupled to the pushrod or wire at the distal end of the tube through a clevis so that axialmovement of the push rod is translated to rotational or pivotal movementof the end effector. The end effector is formed of both conductivematerial and non-conductive material; the non-conductive materialsurrounding all of the conductive material but for a selected electrodesurface and a selected surface for coupling with an electrical source.

Preferred aspects of the invention include insert molding a conductivemetal in a non-conductive ceramic or plastic end effector.Alternatively, the end effector may be formed by injection molding anon-conductive end effector and plating conductive surfaces onto it.Another preferred method of forming the end effector is by casting aconductive end effector and coating it with an insulating polymer orother insulating material. Preferred conductive surfaces include asingle conductive point electrode rising from or flush with the surfaceof an otherwise non-conductive end effector or a linear electrodesurface on an otherwise non-conductive end effector. Alternatively, theconductive surface may be a plurality of defined conductive electrodesurfaces on an otherwise non-conductive end effector. It is alsopreferred that means be provided for electrically coupling theconductive surface of the end effector to an electrical source throughthe tube and/or the push rod of the endoscopic instrument. When both thetube and the push rod are separately coupled to different poles of anelectrical source, as with a bipolar arrangement, means for electricallyinsulating the push rod, clevis, tube and end effectors from each otherare also provided.

In accord with other aspects of the invention, different end effectorsfor endoscopic instruments are provided which use metal cores or spinesas reinforcement for plastic, or which use metal cutting edges as partof a plastic end effector. The end effectors are not necessarily used inconjunction with a cautery application.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevation in partial cross section of the proximal endof an endoscopic instrument with an electrical connection to the tube;

FIG. 1a is an enlarged detail of the tube of the instrument of FIG. 1;

FIG. 1b is a side elevation view of the distal end of the instrument ofFIG. 1;

FIG. 2 is a side elevation schematic view of the distal end of anendoscopic instrument with single action selective cautery end effector;

FIG. 2a is a bottom plan view of the selective cautery end effector ofFIG. 2;

FIG. 2b is a perspective view of the end effector of FIG. 2a;

FIG. 3 is a top plan view of an embodiment of a double action selectivecautery end effector;

FIG. 3a is a side elevation view of the end effector of FIG. 3;

FIG. 3b is a perspective view of a conductive core or skeleton used toinsert mold the end effector of FIG. 3;

FIG. 4 is a view similar to FIG. 3b but of another embodiment ofselective cautery end effector;

FIG. 4a is a perspective view of a conductive core or skeleton used toinsert mold the end effector of FIG. 4;

FIG. 5 is a top plan view of yet another embodiment of selective cauteryend effector;

FIG. 5a is a perspective view of a conductive core or skeleton used toinsert mold the end effector of FIG. 5;

FIG. 6 is a side elevation view of a biopsy forceps jaw end effectorhaving a conductive skeleton insert molded in a non-conductive body;

FIG. 6a is a side elevation view of the conductive skeleton of the endeffector of FIG. 6;

FIG. 6b is a top plan view of the skeleton of FIG. 6;

FIG. 7 is a side elevation view of a biopsy forceps jaw end effector ofinjection molded plastic whose teeth are rendered conductive by anexternal conductive trace;

FIG. 8 is a side elevation view of a biopsy forceps jaw end effectorcast in metal and selectively coated with an insulating polymer;

FIGS. 9a and 9b are side elevation views in partial cross section of anendoscopic tool with bipolar selective cautery end effectors;

FIG. 10a is a transparent side elevation view of an insert moldedarthroscopic end effector with a conductive razor blade insert; and

FIG. 10b is a transparent perspective view of the arthroscopic endeffector of FIG. 10a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An endoscopic surgical instrument is shown in FIGS. 1, 1a and 1b andgenerally includes a metal (e.g., aluminum) tube 15 surrounded by aperipheral insulating shrink wrap layer of plastic 20, a clevis 30, endeffectors 40, actuating means 50, and a push rod 60. The clevis 30 isusually a separately formed aluminum piece which fixedly engagesaluminum tube 15 and also engages the end effectors 40 which pivotallyengage clevis 30 at pivot pin 45. End effectors 40 generally includestwo members 90, 92 at least one of which is pivotally engaged to clevis30. When both members are pivotally engaged, the instrument is said tobe "double acting" whereas when only one of the members 90, 92 ispivotally engaged, the instrument is said to be "single acting". Thepush rod 60, which is also usually formed of aluminum or stainlesssteel, is engaged at its distal end 65 to the end effector 40 and isconnected its proximal end 70 to a manually operable actuating means 50.In use, the endoscopic instrument is inserted with the members 90, 92 ofthe end effector 40 in the closed position 129, through a trocar tubeinto a body incision. The members 90, 92 can be opened and closed, asindicated by arrows 127, by reciprocal motion, as indicated by arrows62, of push rod 60 which results from operation, as indicated by arrows52, of the manual actuating means 50.

The endoscopic instrument shown in FIG. 1 includes an electricalconnector 115 which couples an electrical source to the tube 15 and thusto the clevis 30 and the end effector 40 for monopolar cautery.

Referring now to FIG. 2, an end effector 290 according to the inventionis shown mounted on a clevis 30 by a clevis pin 45 at the distal end ofan endoscopic instrument such as the one shown in FIG. 1. The endeffector shown in FIG. 2 is a "single acting" end effector sincemovement of push rod 60 effects rotation of end effector member 290about clevis pin 45 while a stationary member 292 is fixedly coupled tothe clevis 30 or tube 15.

Turning to FIGS. 2a and 2b with reference to FIG. 2, end effector 290generally includes a distal portion 212 and a proximal portion 210 witha pivot bore 206 therebetween. The end effector is mounted on the clevis30 by a clevis pin 45 which passes through the pivot bore 206 of the endeffector 290 and engages the clevis 30. The proximal portion 210 of theend effector 290 includes a second "actuation" bore 208 which receiveseither a link 67 which couples the end effector to the push rod 60 orthe push rod itself so that axial movement of the push rod 60 throughthe tube 15 causes rotation of the end effector about the clevis pin 45.The distal portion 212 of the end effector generally includes a workingsurface 202 which in this embodiment is a gripping surface. In accordwith the invention, the end effector 290 is constructed ofnon-conductive material such as molded plastic or non-conductiveceramic. In order to provide a selected conductive surface within theworking surface 202 and to strengthen the end effector 290, a metalspine 204 is insert molded in the non-conductive material of which theend effector is made. In this embodiment, the conductive spine 204occupies part of the distal portion 212 of the end effector, extendingalong a relatively thin surface 205 within the working surface 202 ofthe end effector, penetrating within the body of the end effector to aportion 216 which is totally insulated by the non-conductive body of theend effector and emerging at 214 to communicate with the pivot bore 206.As will be appreciated by those skilled in the art, the selected narrowconductive surface 205 of end effector 290 is electrically coupled tothe tube 15 via the conductive clevis pin 45 which extends through thepivot bore 206, and via the conductive clevis 30 which couples the tubeand the pin. When an electrical source is coupled to the tube 15 asshown in prior art FIG. 1, end effector 290 becomes an electrocauteryelectrode with a very well defined conductive surface 205. Duringelectrocautery operations, surrounding tissues are protected from theconductive surface 205 by the otherwise non-conductive body of the endeffector 290. In order to insulate the conductive clevis 30 fromsurrounding tissues, the plastic layer 20 covering tube 15 is preferablyextended to cover the clevis 30 as shown in FIG. 2.

The method of insert molding a conductive spine or skeleton in anon-conductive end effector can be used to produce a variety of singleacting or double acting instruments. FIGS. 3 through 6b show but a fewembodiments of the invention using this method of insert molding. FIGS.3, 3a and 3b show a gripper end effector 390 with a very smallconductive spot electrode 305 formed on its working surface 302 by aninsert molded conductive spine 304. As with the embodiment of FIG. 2,this spine 304 extends into the body of the end effector to create anelectrical coupling at 314 through the pivot bore 306 of the endeffector 390. Thus, the spot electrode 305 formed on the working surface302 of the end effector 390 receives its electrical connection throughthe clevis and tube as described above.

FIGS. 4 and 4a show another embodiment of end effector 490 having apointed electrode 405 rising from the working surface 402. In thisembodiment, inserted spine 404 extends into the body of the end effectorto a portion 414 for an electrical coupling through actuation bore 408of the end effector. With end effector 490, an electrical source iscoupled to the push rod of an endoscopic instrument as described indetail below with reference to FIGS. 9a and 9b. It should be noted thatin this embodiment, the pivot bore 406 is non-conductive and insulatedfrom the spine 404 by the non-conductive body of the end effector 490.similarly, in the end effectors 290, 390 described above, the actuationbores 208, 308 are non-conductive and insulated from the pivot bores206, 306 by the non-conductive body of the end effector. As described indetail below with reference to FIGS. 9a and 9b, using one end effectormember with an electrode surface coupled to the pivot bore and anotherend effector member with an electrode surface coupled to the actuationbore makes endoscopic bipolar selective cautery possible.

The inserted conductive spine may be more than just a single element"spine" or "core". FIGS. 5 and 5a show an embodiment of end effector 590having three surface point electrodes 505, 506, 507 on its workingsurface 502. These three electrodes are formed by inserting a fork-likeskeleton 504 in the mold for the end effector 590. The fork-likeskeleton 504 has three tines which extend from the surface pointsthrough the body of the otherwise non-conductive end effector to acollar 514 which may be aligned with either the pivot bore or theactuator bore of the end effector. It will be appreciated by thoseskilled in the art that the metal tines not only serve to provide aselective cautery function, but also act to strengthen the overallstructure of the end effector.

FIGS. 6, 6a, and 6b show a more elaborate skeleton 604 used to constructa biopsy forceps jaw end effector 690 with conductive teeth 605. In thisembodiment, conductive skeleton insert 604 is formed by casting,stamping, or by photochemical milling or machining and is preferablyprovided with a number of fixation (staking) holes 620. The skeleton isused as an insert for an insert-type injection mold which is filled withplastic. While the skeleton 604 is inserted in the mold, thenon-conductive plastic or ceramic material flows through these stakingholes 620 to anchor the skeleton and strengthen the end effector. Theproximal end 614 of the skeleton may enter the pivot bore 606 or theactuator bore 608 as shown. Moreover, the skeleton may exit the endeffector shell at the proximal end as indicated by dotted line 609whereby the actuator bore 608 in the proximal end 614 of the skeleton isavailable for an electrically conductive coupling with a push rod.

In addition to insert molding, a selectively conductive end effector canbe formed by injection molding with subsequent selective plating. FIG. 7shows an injection molded ceramic (e.g. alumina, zirconia, etc.) biopsyforceps jaw 790 with plated traces 714, 704, 705 for electricalconductivity in the teeth and at the proximal connection 708 to a pushrod or other actuator. The plated traces are provided on the ceramicsurface or in the ceramic and may be applied by sputtering or by othersuitable procedures.

Besides molding, cast end effectors can be made selectively conductiveby coating. FIG. 8 shows a cast biopsy forceps jaw 890 coated with avery thin highly insulating polymer 891 such as PARYLENE manufactured byUnion Carbide. The teeth 805 and proximal connection 814 are uncoatedand thus conductive. These conductive portions can be masked beforecoating the jaw or can be ground or polished to remove portions of thecoating after the jaw is coated. The PARYLENE is preferably depositedevenly on the jaw surfaces by applying it in a tumbling or other processin a vacuum at room temperature with the teeth 805 and proximalconnection 814 masked before coating. It will also be appreciated thatremoval of the polymer from the proximal connection can be effected bydrilling hole 808 after coating to provide an uninsulated surface withinhole 808.

As mentioned above, any of the embodiments of the selectively conductiveend effectors can be made to electrically couple with either the clevispin or the push rod, and a double acting bipolar selective cautery endeffector can be constructed by making one of the end effector elementselectrically couple with the tube and the other couple with the push rod(provided the tube and push rod are electrically isolated from eachother). FIGS. 9a and 9b show a bipolar selective cautery endoscopicinstrument where one pole is coupled through the tube 15 and the otherthrough the push rod 60. As mentioned above, with reference to FIG. 1,it is known to couple an electrical source to the tube 15 as withconnector 115 shown in both FIG. 1 and FIG. 9a. FIG. 9a also shows,however, an electrical connection through connector 160 which coupleswith the proximal end 70 of the push rod 60. With both of theseconnections, it is possible to provide bipolar cautery at the distal endof the instrument shown in FIG. 9b.

FIG. 9b shows a conductive clevis 30 with a conductive clevis pin 45electrically coupling the pivot bore 906 of an end effector member 90.End effector member 90 is constructed in a manner similar to the endeffector 390 shown in FIG. 3a insofar as the selected conductive portionon the working surface of the end effector is electrically coupled withthe pivot bore while the rest of the end effector is non-conductive. Inthis manner, the electrical pole coupled to connector 115 in FIG. 9a iscoupled through the tube 15, the clevis 30, and the clevis pin 45 to theselected conductive portion of end effector 90 via the pivot bore 906.FIG. 9b also shows push rod 60 electrically insulated from clevis 30 bya non-conductive lining 23 on the interior surface of clevis 30. Pushrod 60 is coupled to the actuation bores 908, 909 of end effectormembers 90 and 92 by conductive links 67. End effector member 92 isconstructed in a manner similar to the end effector 490 in FIG. 4insofar as the selected conductive portion on the working surface of theend effector is electrically coupled with the actuation bore while therest of the end effector is non-conductive. In this manner, theelectrical pole coupled to connector 160 in FIG. 9a is coupled throughthe push rod 60 and the conductive links 67 to the selected conductiveportion of end effector member 92 via the actuation bore 909. Becauseboth end effectors are non-conductive but for their selected conductivesurface and proximal connection to either the pivot bore or theactuation bore as described above, the conductive link 67 makes noelectrical coupling to end effector member 90 and the conductive clevis30 and clevis pin 45 make no electrical coupling to end effector member92. FIGS. 10a and 10b show a surgical punch end effector having astationary jaw 1090 and a movable jaw 1092. The stationary jaw has ashank portion 1030 which fits lockingly inside tube 15 and which isprovided with a throughbore 1022 for receiving a push rod 60. Themovable jaw is pivotally attached to the stationary jaw by matingsurfaces 1012, 1014 and is linked to the distal end of the push rod 60by a pin 1008. The stationary jaw 1090 is provided with an opening 1020into which the movable jaw 1092 pivots. In this way the stationary jawfunctions as a die and the movable jaw as a punch for cutting throughtissue. In accord with the invention, the end effector of FIG.s 10a and10b is constructed of injection molded plastic or ceramic with apreformed and ground razor blade 1005 insert molded into the opening1020 of the stationary jaw 1090. The movable jaw 1092 is provided withan overlapping rim 1093 which covers the blade 1005 when the jaws areclosed. The razor blade 1005 is typically conductive, while theremainder of the end effector is non-conductive. If desired, theconductive blade 1005 can be electrically coupled to the tube 15 in anyof the ways discussed above.

There have been described and illustrated herein several embodiments ofa selectively conductive end effector member and means for electricallycoupling end effector members to an electrical source. While particularembodiments of the invention have been described, it is not intendedthat the invention be limited thereto, as it is intended that theinvention be as broad in scope as the art will allow and that thespecification be read likewise. Thus, while particular types of endeffectors, namely grippers, and arthroscopic and biopsy jaws, have beendisclosed, it will be appreciated that other types of end effectors canembody the invention. It is possible, therefore to use the methods andmaterials disclosed herein to create other types of end effectors suchas cutters, dissectors, scissors, and the like. Also, while specificclevis, push rod and actuation means have been shown, it will berecognized that the selective cautery end effectors of the inventioncould be used with other kinds of endoscopic instruments having somewhatdifferent clevis and actuation mechanisms. Thus, while the selectivecautery end effector members have been disclosed as having pivot boresand actuation bores, it will be appreciated that other arrangements canbe utilized. Likewise, it will be understood that stationary endeffector members without pivot or actuation bores can be constructedaccording to the invention, for example for use in bipolar single actionend effectors.

It will further be appreciated by those skilled in the art that whileparticular conductive and non-conductive materials have been disclosed,other materials could be used as well. In addition, while non-conductiveend effector members with conductive cores have been shown for thepurpose of selective cautery, it will also be recognized that a metalliccore in a non-metallic end effector member strengthens the member andallows the construction of less expensive non-metallic end effectorswhich may be useful without cautery. It will therefore be appreciated bythose skilled in the art that yet other modifications could be made tothe provided invention without deviating from its spirit and scope as soclaimed.

We claim:
 1. A method of manufacturing an end effector for an endoscopic surgical instrument having an actuation means, comprising:forming a metallic skeleton by a process chosen from casting, stamping or photochemically milling; and molding a non-conductive body around said metallic skeleton, said non-conductive body having a proximal end with means for coupling to the actuation means, and a distal end with means for cutting, gripping, clamping, or otherwise contacting tissue.
 2. A method according to claim 1, wherein:in said molding step, said metallic skeleton is located in a manner such that a distal end of said metallic skeleton extends to a surface portion of said non-conductive body.
 3. A method according to claim 1, wherein:said metallic skeleton is formed with at least one pivot hole.
 4. A method according to claim 1, wherein:said metallic skeleton is formed with at least one hole which comprises said means for coupling to the actuation means.
 5. A method according to claim 1, wherein:said metallic skeleton is formed with at least one fixation hole through which said non-conductive body extends.
 6. A method according to claim 3, wherein:said metallic skeleton is formed with at least one hole which comprises said means for coupling to the actuation means, and said metallic skeleton is formed with at least one fixation hole through which said non-conductive body extends.
 7. A method according to claim 1, wherein:said molding step comprises insert molding said metallic skeleton in said non-conductive body.
 8. A method according to claim 1, wherein:said metallic skeleton comprises a metal core having a plurality of tines.
 9. A method of manufacturing an end effector for an endoscopic surgical instrument having an actuation means and a clevis means, comprising:casting a conductive body according to an investment casting process, said conductive body having a proximal end, and a surface portion adjacent where said end effector grasps, clamps cuts, or otherwise contacts a tissue, said cast conductive body including means for coupling said end effector to the actuation means and means for coupling said end effector to the clevis means; coating said cast conductive body with a non-conductive coating except for at least one selected first location on said surface portion on said conductive body, and except for at least one selected second location located at at least one of said means for coupling said end effector to the clevis means and said means for coupling said end effector to the actuation means; and masking said cast conductive body with masking means at said at least one selected first location and at said at least one selected second location prior to said step of coating, and removing said masking means after said step of coating. 